In the tradition of "Release early, release often", the Netbeans team has released version 6.5, continuing the rapid release cycle the project set with 5.5, 6.0, and 6.1. There many new features, most notably support for Groovy /Grails and PHP. Here's a short list of the other "new and notables":

A new "Compile and Deploy on Save" feature for Java applications.

Support for the Nimbus look and feel in the Swing GUI builder (Matisse)

Big improvements in the JavaScript support, particularly in the area of debugging.

Support for Ruby on Rails 2.1 (JRuby 1.1.4 is bundled)

Improved SQL support, including SQL history and editor auto-completion.

There is also an early access release of Python support in Netbeans that is available as a separate download.